BOS_TOKEN = '[PAD]'
EOS_TOKEN = '[SEP]'
CLS_TOKEN = '[CLS]'
SPACE_TOKEN = '[unused1]'
UNK_TOKEN = '[UNK]'
SPECIAL_TOKENS = [BOS_TOKEN, EOS_TOKEN, CLS_TOKEN, SPACE_TOKEN, UNK_TOKEN]
TRAIN = 'train'
EVAL = 'eval'
PREDICT = 'infer'
